This sounds like complete houseboat to me, they've not even said they don't have enough players, they're requesting it to be 'prudent'. Someone pointed out they've played 30 different players in the League Cup this season plus 8 other senior players who were left out altogether. So apparently 25 players are unavailable.
Somehow I get the feeling they'll find the players for their League 1 FA Cup game. I've also seen a theory that they're doing this to push back potential PL games being rearranged for the one free slot in Jan while Salah and Mane are away.